Theerawongnukul, H., Ratana-Ubol, A. and Keeratiburana, Y. (2014) “The Development of A Program to Enhance Self-Esteem and Social Skills of Non-Formal Education Students”, Journal of Education Studies, Chulalongkorn University. Bangkok, Thailand, 42, pp. 92–109. available at: https://so02.tci-thaijo.org/index.php/EDUCU/article/view/26462 (accessed: 3 October 2026).